With the advent of digital video technology, many new and exciting products are available. One such product is a digital videocassette recorders (VCR), which receives an analog television broadcast, converts it into an MPEG (“Motion Picture Expert Group”) digital format and stores the MPEG video. By storing the television broadcast signals in a digital format, the user may view the recorded digital images in a variety of ways, including fast forward, rewind, pause, etc.
The digital VCR allows a user to store various programs and to amass a substantial amount of video data. Such video data may span several hours of program viewing. When the user desires to watch a particular program or particular section of a program, the user inputs the particular start time that corresponds with the beginning of a program or the desired section. For example, if the user has stored programs that are broadcast via a network channel that begin at 7:00 p.m. and end at 10:00 p.m. and desires to watch the program that began at 8:30, the user would enter 8:30 p.m. as the start time.
As is known, MPEG video images are time-stamped, for example every 2 kilobytes of data. As such, when the user enters a particular start time, the time-stamps are used to identify the start of the corresponding data. An issue arises with MPEG video data in that the amount of data stored over time is not linear, i.e., it is a non-linear monotonic function. As is known, when an action scene is being recorded, substantially more digital information is used to represent those images than relatively stationary images. Thus, over time the storage of MPEG video data is a non-linear.
As with any commercial product speed in responding to user input commands are important. If the digital VCR determines the starting point of a program by scanning the time stamps and seeking a match, a significant amount of processing resources and time may be consumed. Such processing may be noticeable to the user in a detrimental way. Thus, it is important for commercially viable digital VCRs to incorporate a technique that efficiently seeks the start of MPEG video data that is to be subsequently viewed.
Therefore, a need exists for a method and apparatus for successive linear approximation to obtain a specific point of a non-linear monotonic function such that fast seeking of MPEG video can be realized.